Deprecation warning due to invalid escape sequences in Python 3.8

Start by running the Python 3.8 command shown in the issue, then inspect the reported expressions in test/test_samplefile.py and odml/rdf/query_creator.py. Update the affected string literals so the warnings are no longer emitted, and rerun the command to confirm the reported invalid-escape warnings are gone.

Deprecation warnings are emitted in Python 3.8 for invalid escape sequences. Escaping them or using raw strings will fix this issue.

find . -iname '*.py'  | xargs -P 4 -I{} python3.8 -Wall -m py_compile {}                               
./test/test_samplefile.py:41: DeprecationWarning: invalid escape sequence \s
  offset = len(re.compile('(\s*)').match(lines[0]).group())
./test/test_samplefile.py:43: DeprecationWarning: invalid escape sequence \w
  '[\w:]+)\])?(\s+linked to (?P<link>[\w/]+))?')
./odml/rdf/query_creator.py:91: DeprecationWarning: invalid escape sequence \(
  doc_pattern = re.compile("(doc|document)\(.*?\)")
./odml/rdf/query_creator.py:96: DeprecationWarning: invalid escape sequence \(
  sec_pattern = re.compile("(sec|section)\(.*?\)")
./odml/rdf/query_creator.py:101: DeprecationWarning: invalid escape sequence \(
  prop_pattern = re.compile("(prop|property)\(.*?\)")
./odml/rdf/query_creator.py:107: DeprecationWarning: invalid escape sequence \(
  p = re.compile("[\(|, ](id|author|date|version|repository|sections)[\)|,]")
./odml/rdf/query_creator.py:112: DeprecationWarning: invalid escape sequence \(
  p = re.compile("[\(|, ](id|name|definition|type|repository|reference|sections|properties)[\)|,]")
./odml/rdf/query_creator.py:117: DeprecationWarning: invalid escape sequence \(
  p = re.compile("[\(|, ](id|name|definition|dtype|unit|uncertainty|reference|value_origin)[\)|,]")
./odml/rdf/query_creator.py:153: DeprecationWarning: invalid escape sequence \(
  doc_pattern = re.compile("(doc|document)\(.*?\)")
./odml/rdf/query_creator.py:158: DeprecationWarning: invalid escape sequence \(
  sec_pattern = re.compile("(sec|section)\(.*?\)")
./odml/rdf/query_creator.py:163: DeprecationWarning: invalid escape sequence \(
  prop_pattern = re.compile("(prop|property)\(.*?\)")
./odml/rdf/query_creator.py:171: DeprecationWarning: invalid escape sequence \(
  p = re.compile("[, |\(](id|author|date|version|repository|sections):(.*?)[,|\)]")
./odml/rdf/query_creator.py:176: DeprecationWarning: invalid escape sequence \(
  p = re.compile("[, |\(](id|name|definition|type|repository|reference|sections|properties):(.*?)[,|\)]")
./odml/rdf/query_creator.py:181: DeprecationWarning: invalid escape sequence \(
  p = re.compile("[, |\(](id|name|definition|dtype|unit|uncertainty|reference|value_origin):(.*?)[,|\)]")
./odml/rdf/query_creator.py:185: DeprecationWarning: invalid escape sequence \[
  p_value = re.compile("value:\[(.*)]")